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This study aimed to develop a structural analysis method to replace and validate large-scale gas gun tests for evaluating the impact resistance of electronic equipment. By measuring projectile's deceleration through experiments and simulations, stress and strain during collisions were quantified. It was demonstrated that optimizing projectile and electronic equipment designs could enhance impact resistance. Simulation results indicated that changes in projectile velocity and head angle led to variations in maximum deceleration and penetration depth, with decreasing the head angle proving more effective in reducing maximum deceleration. Comparisons between experimental and simulation results showed good agreement, particularly in plots between maximum deceleration and target collision depth. As the head angle increased, there was a tendency for maximum deceleration to increase and target penetration depth to decrease. Comparing peak deceleration curves from gas gun tests and simulations revealed similar trends, indicating consistent results. This research provides important information for evaluating the impact resistance of electronic equipment and demonstrates that combining experiments with simulations can yield more reliable results.

The development of new advanced functionalities, miniaturization, and the aim of obtaining optimized performance in electronic devices significantly impacts their electromagnetic compatibility (EMC). As electronic components become more densely packed on a printed circuit board (PCB), unintended coupling between components can cause electromagnetic interference (EMI). These requirements result in design restrictions that make using a board level shield (BLS) essential in reducing intra-system EMI in PCB designs. This contribution focuses on studying and characterizing a BLS solution based on combining a noise suppression sheet (NSS) with an aluminum layer to reduce intra-system EMI coupling. This hybrid solution has the advantage of providing a shielding option that does not require any electronic redesign. It does not need a footprint or a ground connection as it can be affixed over the EMI source. The solution is expected to provide higher attenuation levels than using only an NSS by combining the absorbing properties of the magnetic material and the loss mechanism of the metal. In order to verify the effectiveness of the hybrid BLS proposed solution, the magnetic near-field emissions of an EMI source are analyzed in this study. The experimental measurements and simulated results demonstrate a significant increase (51.6 dB at 1 GHz) in the shielding effectiveness (SE) provided by the proposed solution compared to a conventional NSS. [ABSTRACT FROM AUTHOR]

• Thermal battery resilience under high-impact conditions was assessed to sustain continual power supply for electronic devices equipped with artillery projectiles. • Honeycomb buffering devices with different wall thicknesses were adopted to compare their energy-absorption capacities. • Large-scale gas-gun tests and finite element simulations comparing buffering devices revealed distinct deformation patterns influencing impact deceleration. • The thermal battery retrieved from the gas-gun test proved to have reliable impact resilience for the target performance. Modern warfare relies heavily on electronic equipment, necessitating reliable energy sources like thermal batteries. Assessing their impact resilience, a study employed honeycomb-structured Al plates as buffering devices in a large-scale gas gun simulating artillery fire. Comparison between peak curves from gas-gun tests and simulations with varying honeycomb wall thicknesses revealed unique patterns, attributed to the buffering device's deformation-restoration process. Different honeycomb wall thicknesses led to varying deformation behavior and impact deceleration, complicating effective energy absorption assessment. Stepped honeycomb wall designs aimed to balance compression, extending energy absorption and reducing deceleration peaks. Prototype honeycomb buffering devices showed improved energy absorption and reduced deceleration during gas-gun tests. Gas-gun tests highlighted complexities in energy absorption assessment, with designs proposing improved energy absorption and reduced deceleration. The actual gas-gun test launched a projectile equipped with a thermal battery and buffering device, resulting in slight casing deformation, while battery cells remained intact, exceeding the standard discharge time (1 h). [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the effects of extreme thermal fluctuations on the reliability of solder joints were investigated. For this purpose, the solder joints in insulated-gate bipolar transistor (IGBT) devices were exposed to the conventional thermal cycling and the thermal shock cycling (TSC) tests. The finite element method (FEM) simulation results indicated that the accumulated creep energy in solder layer is much higher under the TSC process. Moreover, the stress triaxiality, as the indicator of damage initiation, is more concentrated in the TSC-exposed sample. It is believed that the higher heating and cooling rates along with the higher peak temperatures lead to the damage susceptibility of solder joints under TSC process. The experimental results confirm that the void formation and growth significantly increases in the TSC-exposed sample, which is consistent with the simulation outcomes. Moreover, the shear test reveals that the ultimate strength of sample under the thermal shocking severely decreases which is due to the void growth and the intensified elemental heterogeneity. [ABSTRACT FROM AUTHOR]